The present invention relates to portable imprinters and, in particular, to such imprinters useful for recording credit card sales transactions.
The pervasive presence of credit extension in modern day business transactions through the vehicle of the credit card has resulted in the institution of credit card transactions in almost every facet of commerce. As a direct result of this development, a need has arisen for an efficient and durable imprinting mechanism which may be employed in a wide variety of transactional situations not heretofore contemplated and thereby not capable of accommodation by conventional imprinters. Thus, such factors as size, cost, ease of operation and mechanical reliability of conventional imprinters has severely curtailed the growth of their employment in such areas as door-to-door sales and other transactions which commend themselves to a portable imprinter unit.
While there are various portable importable imprinters which have been developed and have been known in the art, their use is quite limited as they suffer from some of the same defects noted with regard to imprinters generally. That is, the imprinters are often complex and expensive, and likewise are often prepared from materials which tend to corrode or otherwise break down after prolonged usage. Many of the imprinters are incapable of providing a uniform print density regardless of the thickness of the document involved, a difficulty frequently attending the usage of a portable imprinter mechanism.
One of the major difficulties encountered in the use of imprinters, both portable and stationary, has been the tendency of the imprinter roller mechanism to lock into printing position with the result that the document or receipt is damaged or smudged on the return cycle of the roller. Prior art attempts to alleviate this difficulty have resulted in the development of extremely complex and costly mechanisms which have proved to be more costly to manufacture and maintain than the units they were intended to replace. The combination of increased costs and reduced service life has kept the imprinter financially out of the reach of many small merchants whose overhead is incapable of supporting such an item, and has likewise precluded the development of inexpensive portable imprinters for the aforementioned uses.